# World Time Check vs Prime Factorization

The clearest difference is review sentiment: Prime Factorization at 100% against World Time Check's 14%. Prime Factorization also leads on price (Free vs $0.99) and rating (4.4 vs 1.0). On update cadence, ads, in-app purchases and device support there is nothing between them.

Prime Factorization is free to download; World Time Check costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Prime Factorization holds the better App Store score, 4.4 against 1.0. That said, the two scores are not equally well evidenced: Prime Factorization has 5 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 14% of World Time Check's written reviews are positive against 100% of Prime Factorization's.

World Time Check ships an update every 5 months, Prime Factorization every 3 months. The most recent releases landed on September 24, 2026 and September 30, 2026 respectively.

## The numbers

| Metric | World Time Check | Prime Factorization |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | [1.0 (1 ratings)](https://appshunter.io/ios/app/world-time-check/id521449019/reviews) | **[4.4 (5 ratings)](https://appshunter.io/ios/app/prime-factorization/id528980227/reviews)** |
| Number of ratings | 1 | **5** |
| Positive reviews | 14.3% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 3 months** |
| Monetization | Paid | **Free** |
| Size | 1 MB | 2 MB |
| Requires iOS | 15.5 | **8.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [SHUJI FUKUNAGA](https://appshunter.io/developer/469076836) | [Sohei Mori](https://appshunter.io/developer/528980270) |

## What reviewers say

### World Time Check

[App page](https://appshunter.io/ios/app/world-time-check/id521449019)

Easily view and compare current times across multiple global cities simultaneously. This utility helps you coordinate international meetings or plan travel by showing time differences with intuitive scrolling and real-time synchronization.

**Highlights:** Multiple cities at once, Real-time sync, Check future times, Easy city search, Custom date & time, Daylight saving support

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Prime Factorization

[App page](https://appshunter.io/ios/app/prime-factorization/id528980227)

This utility app breaks down integers into their prime factors. It also calculates the number and sum of divisors, lists all divisors, and identifies specific number types like prime, perfect, abundant, or deficient.

**Highlights:** Prime factorization of integers, Calculate number of divisors, Sum of divisors calculation, List all divisors, Identify prime numbers, Identify perfect, abundant, deficient numbers

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is World Time Check free?

World Time Check costs $0.99, with no in-app purchases.

### Is Prime Factorization free?

Prime Factorization is free to download, with no in-app purchases.

### Which has better reviews, World Time Check or Prime Factorization?

Prime Factorization is rated higher. World Time Check averages 1.0 out of 5 from 1 ratings, while Prime Factorization averages 4.4 from 5 ratings.

### Do World Time Check or Prime Factorization have ads?

Neither World Time Check nor Prime Factorization shows ads.

### Which is updated more often, World Time Check or Prime Factorization?

World Time Check ships an update every 5 months, and Prime Factorization every 3 months. Most recently, World Time Check was updated on September 24, 2026 and Prime Factorization on September 30, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*